Mary Cernicek, public affairs officer with the Bridger-Teton National Forest, said the two forests already share some resources such as road crews and equipment operators.

The largest forest currently in the lower 48 is the Humboldt-Toiyabe National Forest in northern Nevada, which has 6.3 million acres. Cernicek said some supervisors there have to fly between sections of the forest.

Kniffy Hamilton, retired supervisor of the Bridger-Teton National Forest, said the two forests are dramatically different. Caribou-Targhee has phosphate mining and more roads, motorized recreation and timber harvest. The Bridger-Teton is largely roadless and wilderness areas with and some oil and gas drilling.

"It's just a lot of land to manage," Hamilton said. "I think you would lose track as forest supervisor of everything that is going on. I don't think it would better serve the whole constituency."

Hamilton also said it would be complicated to manage a forest that sprawled into two states, drawing interest from two state governors, two congressional delegations and nearly two dozen counties.

Teton County Commissioner Hank Phibbs said a merger would be "nothing short of a management disaster." He said he's concerned it would be difficult for one person to reconcile the management philosophies of the two forests with their different uses.

Cernicek said most of the savings in reaching the $1 million target would come from locating a combined supervisor's office in either Idaho or Wyoming. The combined budget of both forests in 2012 was about $33 million.

The Forest Service owns the Bridger-Teton office in Jackson and leases Caribou-Targhee's office in Idaho Falls. Cernicek said about 40 people work out of the Jackson office.

Renny MacKay, spokesman for Wyoming Gov. Matt Mead, said that if the forests are merged Mead believes it's critical that the headquarters be in Wyoming.

Officials from the Bridger-Teton and Caribou-Targhee forests have until the end of January to produce a recommendation saying whether the forests should study a merger. The regional forester will make the final decision.